Chapter 12: Cold and Dark

Water bath: 10 min for jams and pickles in half-litre jars; 20 to 25 min for whole fruit and acidified tomatoes in litre jars; 5 min more per 300 m altitude; tomatoes only with added acid

To check against

USDA Complete Guide to Home Canning (2015) / NCHFP process tables; German BZfE guidance on Einkochen (more conservative on tomatoes); Weck's own tables

The verdict

AMENDED

Found

nchfp.uga.edu/how/can/how-do-i-can-tomatoes/whole-or-halv… (boiling water, 0 to 1,000 ft: pints 40, quarts 45 min); nchfp.uga.edu/how/can/how-do-i-can-tomatoes/crushed-tomat… (pints 35, quarts 45); nchfp.uga.edu/how/can/canning-fruits-and-fruit-products/c… (quarts hot 20, raw 25), .../plums-halved-or-whole/ (quarts 25), .../apples-sliced/ (20); nchfp.uga.edu/how/ferment/recipes/dill-pickles/ (pints 10); nchfp.uga.edu/how/can/general-information/sterilization-o… (jams under 10 min need sterile jars)

Note

Jams and pickles 10 min in half-litre jars and whole fruit 20 to 25 min in litre jars are confirmed. Acidified tomatoes are wrong and dangerous: USDA needs 45 min for litre (quart) jars of whole, halved or crushed tomatoes, 40 min for pints (85 min for raw pack without liquid), always with added acid. Altitude: USDA adds 5 min for 1,001 to 3,000 ft and 10 min for 3,001 to 6,000 ft, not 5 min per 300 m; irrelevant at Berlin's height, but the rule as written is not USDA's. BZfE and Weck tables not opened. Proposed: "10 minutes for jams and pickles in half-litre jars, 20 to 25 for whole fruit in litre jars, and 45 for tomatoes in litre jars, always with the acid added; above 300 metres, add 5 minutes, and more in the mountains."

Pressure canner: 116 °C at 0.7 bar (10 psi) at sea level; vent 10 min; meat and stock in litre jars 90 min; beans, carrots, beetroot 25 to 30 min; restart timing if pressure drops

To check against

NCHFP tables (weighted gauge 10 psi, dial gauge 11 psi; quart jars: meat 90, green beans 25, carrots 30, beets 35 min); check beetroot figure

The verdict

AMENDED

Found

nchfp.uga.edu/how/can/preparing-and-canning-poultry-red-m… (quarts 90, pints 75; weighted gauge 10 lb at 0 to 1,000 ft, dial 11 lb at 0 to 2,000 ft); .../meat-stock/ (quarts 25); nchfp.uga.edu/how/can/canning-vegetables-and-vegetable-pr… (quarts 25); .../carrots-sliced-or-diced/ (quarts 30); .../beets-whole-cubed-or-sliced/ (quarts 35); nchfp.uga.edu/publications/uga-publications/using-pressur… (vent 10 min; if pressure drops, return to pressure and restart timing from the beginning); nchfp.uga.edu/how/can/general-information/temperatures-fo… (240 to 250 °F)

Note

Confirmed: 10 psi (0.69 bar) ≈ 116 °C, vent 10 min, meat quarts 90 min, beans 25, carrots 30, restart on pressure drop. Amend: beetroot is 35 min in litre jars, not 25 to 30; a dial gauge must read 11 psi (0.76 bar), not 10, at 0 to 600 m. Stock at 90 min is over-processing (USDA 25), safe but not needed. Proposed: "Meat in litre jars 90 minutes; stock 25; beans 25, carrots 30, beetroot 35; with a weight, 10 pounds, with a dial gauge, 11."

Discard signs (lifted lid, leak, cloudiness, bubbles, spurting, off smell); disposal by burning or deep burial; wash surfaces with lye water

To check against

NCHFP "Identifying and handling spoiled canned food" (detoxify with 1 part bleach to 5 parts water; jars boiled 30 min); confirm that lye water is an acceptable substitute or amend

The verdict

AMENDED

Found

nchfp.uga.edu/how/can/general-information/identifying-and… (signs: unsealed or swollen lid, streaks of dried food from the top, rising bubbles, unnatural colour, off odour, spurting, cotton-like mould; unsealed or leaking suspect jars detoxified by boiling 30 min in a covered pot, gloves; surfaces 1 part bleach to 5 parts water, 30 min, twice); CDC BMBL 6th ed., agent summary C. botulinum, printed p. 338 (NaOCl 0.1 % or NaOH 0.1 N readily inactivate BoNT on surfaces; 0.6 % NaOCl also kills spores)

Note

Signs confirmed; add streaks down the jar and mould. Disposal: NCHFP detoxifies by boiling jar, lid and contents 30 min before disposal; burying is fine after that; burning a sealed jar risks it bursting. Lye is acceptable for the toxin only at known strength: 0.1 N NaOH is 4 g per litre (BMBL). Wood-ash lye is of unknown strength and does not kill spores. Wear gloves: toxin through broken skin is dangerous (NCHFP). Proposed: "Do not taste it. Wearing gloves, boil the jar, lid and contents in a covered pot for 30 minutes, then bury them; wash every surface it touched with bleach, one part to five of water, or with lye of at least 4 grams of caustic soda per litre, left for half an hour."

Botulinum spores survive boiling for hours; pH 4.6 line; 116 to 121 °C kills spores; a few millionths of a gram of toxin kills an adult; toxin destroyed by boiling

To check against

doc 73, 74; FDA Bad Bug Book (botulinum); Sobel 2005 (Clin Infect Dis) on lethal dose; spore heat resistance (D121 about 0.2 min)

The verdict

AMENDED

Found

nchfp.uga.edu/how/can/general-information/ensuring-safe-c… (pH 4.6 line; "Botulinum spores are very hard to destroy at boiling-water temperatures"; 240 to 250 °F, i.e. 116 to 121 °C, at 10 to 15 psig); CDC BMBL 6th ed., printed p. 484 (100 °C for 10 min inactivates BoNT; C. botulinum spores need ≥ 121 °C, 2 h autoclave for volumes over 1 l); en.wikipedia.org/wiki/Botulinum_toxin, citing Arnon et al., JAMA 2001;285:1059 (estimated human lethal dose of type A: 1.3 to 2.1 ng/kg IV, 10 to 13 ng/kg inhaled, about 1 µg/kg by mouth)

Note

pH 4.6, 116 to 121 °C and toxin destroyed by boiling are confirmed. Two amendments. Oral lethal dose is about 1 µg/kg, about 70 µg for an adult, i.e. tens of millionths of a gram, not "a few". And "the spore is unharmed" after an hour's boil overstates: boiling kills most spores, too slowly to kill all; spore D-value (D121 about 0.2 min) not opened this pass. Sobel 2005 not opened. Proposed: "Boil the jar for an hour and enough spores survive to wake in the cellar and make a poison of which less than a ten-thousandth of a gram, swallowed, will kill an adult."

Never reuse a rubber ring that has sealed a low-acid jar; keep three spare sets; stop pressure canning when rings run out

To check against

Book's own rule; Weck's guidance on ring reuse; NCHFP on two-piece lids (single use)

The verdict

AMENDED

Found

weckjars.com/faq/ (Weck: "the FDA recommends disposing of a used canning ring and using a new ring each time"); weckjars.com/canningnotes/ (on a failed seal: "Always use a new rubber ring"); nchfp.uga.edu/how/can/general-information/recommended-jar… (two-piece flat lids single use; lids for Mason jars only)

Note

The manufacturer's and US guidance is stricter than the book: a new ring for every canning, high-acid as well as low-acid. The book's compromise (reuse only for water-bath high-acid food) is a defensible collapse rule but must be stated as its own, and "any ring that seals" is looser than Weck. Three spare sets = three canning seasons per jar at single use, not three spares in reserve; the arithmetic should say so. The stop-when-rings-run-out rule is the book's own and is sound. Proposed: "Weck says a new ring every time; after the Fall, reuse a sound ring only for jam, fruit and pickles, never for a jar that goes into the pressure canner."

Dead chest freezer as first-winter cellar: motor and refrigerant pipes must be removed

To check against

doc 67; German ChemKlimaschutzV / EU F-gas regulation on refrigerant recovery; state the hazard (refrigerant, compressor oil) plainly in draft 2

The verdict

AMENDED

Found

doc 67 (refrigerant section: F-gases R134a/R404A or isobutane R600a; EU F-gas Regulation (EU) 2024/573 requires recovery by certified personnel); gesetze-im-internet.de/elektrog_2015/BJNR173910015.html (ElektroG: freezers are "Wärmeüberträger", Group 1, taken back free of charge at collection points); bsr.de/elektrogeraete (BSR takes freezers free; they contain hazardous substances); en.wikipedia.org/wiki/Isobutane (R600a flammable, explosive limits 1.4 to 8.3 %)

Note

Removal of motor and pipes is right, but the draft must say how, and the hazard. Today in Germany the refrigerant may not be vented: it is recovered by a certified technician or at a recycler (doc 67 citing 2024/573; EU text itself not opened because EUR-Lex blocked the fetch). Freezers since the mid-1990s mostly hold isobutane, which burns; older ones hold CFC or HFC gas and oil in the compressor. Cutting the pipes indoors or near flame is a fire risk. Proposed: "Before the Fall, get a freezer whose gas has been drawn off by a recycler; after it, cut the pipes out of doors, far from any flame, let the gas blow away for a day, and lift the compressor out with its oil, which is poison to the soil."

Sprouted potatoes are safe once sprouts and any green are cut away

To check against

BfR opinion on solanine/glycoalkaloids in potatoes (2018); discard if strongly green or bitter

The verdict

AMENDED

Found

bfr.bund.de/presseinformation/solanin-in-kartoffeln-gruen… (BfR press release 15/2018: old, shrivelled, green or strongly sprouting potatoes are not fit to eat; cut out green parts and eyes generously; do not eat a bitter potato dish; small children should not eat unpeeled potatoes; do not reuse cooking water)

Note

Narrower than the draft: only lightly sprouted, firm potatoes are rescued by cutting; strongly sprouted, shrivelled or green ones are discarded. Proposed: "Eat down the sprouted potatoes first: while they are firm and only a little sprouted, cut the sprouts and eyes out deep and peel them; throw away any that are shrivelled, heavily sprouted or green, and any dish that tastes bitter, and pour away the cooking water."